Blower assembly for self-cleaning convection oven

Abstract

A blower assembly for a cooking appliance having an oven cavity adapted to operate in at least cleaning and convection cooking modes includes a blower element mounted for rotation though a shaft member supported by at least one bearing unit. The shaft member is constituted by a tubular section which is secured to the blower element and a solid shaft section which extends within the tubular section. The solid shaft section is formed from a material having a higher thermal conductivity than the tubular section and concentrically arranged relative to the bearing unit. With this arrangement, the shaft section acts as a heat sink for directing heat, to which the blower element is subjected, away from both the tubular section and the bearing unit. The shaft section preferably terminates within the tubular section at a distance spaced from the blower element such that a thermal air gap is defined within the tubular section.

What is claimed is:  
     
       1. In a cooking appliance including an oven cavity adapted to operate in at least cleaning and convection cooking modes, a blower assembly comprising: 
       at least one bearing unit;  
       a tube supported by the at least one bearing unit for rotation about an axis; and  
       a blower element for developing a flow of air for the oven cavity upon rotation of the blower element, said blower element being drivingly connected to the tube, with the at least one bearing unit rotatably supporting the blower element through the tube.  
     
     
       2. The blower assembly according to claim  1 , further comprising: a heat sink for directing heat, to which the blower element is subjected, away from the at least one bearing unit. 
     
     
       3. The blower assembly according to claim  2 , wherein said heat sink is constituted by a shaft concentrically arranged within said tube. 
     
     
       4. The blower assembly according to claim  3 , wherein said tube has an associated length, with the shaft being shorter than said length. 
     
     
       5. The blower assembly according to claim  4 , wherein at least a portion of the shaft is concentric with the at least one bearing unit. 
     
     
       6. The blower assembly according to claim  4 , further comprising: a thermal air gap, defined within the tube, between the blower element and the shaft. 
     
     
       7. The blower assembly according to claim  3 , wherein the shaft is formed from aluminum. 
     
     
       8. The blower assembly according to claim  7 , wherein the tube is formed from stainless steel. 
     
     
       9. The blower assembly according to claim  2 , further comprising: a mechanism for driving the tube for rotation about said axis. 
     
     
       10. The blower assembly according to claim  9 , wherein said driving mechanism includes a sheeve non-rotatably secured to the tube. 
     
     
       11. The blower assembly according to claim  10 , wherein said sheeve is shrink-fit onto the tube. 
     
     
       12. The blower assembly according to claim  10 , wherein the sheeve is formed from aluminum. 
     
     
       13. The blower assembly according to claim  10 , wherein the tube is rotatably supported solely through the at least one bearing unit which is positioned entirely between the blower element and the sheeve. 
     
     
       14. In a cooking appliance including an oven cavity adapted to operate in at least cleaning and convection cooking modes, a blower assembly comprising: 
       a rotatable blower element arranged in fluid communication with the oven cavity for developing a flow of air for the oven cavity upon rotation of the blower element; and  
       a shaft member for rotatably supporting the blower element, said shaft member being formed from first and second concentrically arranged shaft sections, with the second shaft section being formed of a material having a higher thermal conductivity than the first shaft section.  
     
     
       15. The blower assembly according to claim  14 , wherein the second shaft section is formed from aluminum. 
     
     
       16. The blower assembly according to claim  14 , wherein the first shaft section is constituted by a tube within which the second shaft section extends, said tube having an associated length and the second shaft section being shorter than said length. 
     
     
       17. The blower assembly according to claim  16 , further comprising: a thermal air gap, defined within the tube, between the blower element and the shaft section. 
     
     
       18. The blower assembly according to claim  17 , further comprising: at least one bearing unit rotatably supporting the shaft member for rotation about an axis. 
     
     
       19. The blower assembly according to claim  18 , wherein the second shaft section is concentric with the at least one bearing unit. 
     
     
       20. The blower assembly according to claim  18 , further comprising: a sheeve fixed to the first shaft section for use in rotatably driving the blower element, said sheeve being arranged further from the blower element than the at least one bearing unit.